The invention relates to a method of manufacturing a press felt, the method comprising at least the following steps of: forming a base fabric whose at least one layer comprises at least a first planar component, which is formed from a plurality of longitudinal yarns that travel in the machine direction and transverse yarns that travel in the cross machine direction, and providing the first component with a first transverse joining edge area and a second transverse joining edge area; arranging the first and the second transverse joining edge area of the first component so that they overlap each other; and forming a base fabric with the shape of a closed loop; and attaching at least one batt fibre layer to the base fabric with the shape of a closed loop; and the method comprising attaching the joining edge areas to each other undetachably before the attachment of the batt fibre layer.
The invention further relates to a press felt for a paper machine press section, the press felt comprising: a base fabric, which includes a plurality of longitudinal yarns that travel in the machine direction and a plurality of transverse yarns that travel in the cross machine direction and whose at least one layer is provided with at least a first planar component, which includes a first transverse joining edge area and a second transverse joining edge area and where the joining edge areas are connected to each other, and at least one batt fibre layer, and where the first and the second joining edge area of the first component are arranged so that they overlap each other, and where the joining edge areas are attached to each other undetachably before the attachment of the batt fibre layer.
The invention further relates to a base fabric for a press felt, comprising: a plurality of longitudinal yarns that travel in the machine direction; a plurality of transverse yarns that travel in the cross machine direction; at least a first planar component in at least one base fabric layer, and the first component includes at least a first transverse joining edge area and a second transverse joining edge area, and where the joining edge areas are connected to each other, and the first and the second joining edge area of the first component are arranged to overlap each other; and the joining edge areas are attached to each other undetachebly.
Depending on the press structure, the press section of the paper machine employs a press felt on one or both sides of the web to be dried, into which the water in the web may be absorbed in the pressing phase. The purpose of the press felt is to transport the water away in its structure without letting it back into the web. In the actual pressing, the paper web is conveyed on the felt into an opening between two cylinders, i.e. into a nip. The structure of the felt should allow good absorption of water into the felt in the nip. Press felts include a base fabric which, for example, provides the felt with a necessary space for water. To obtain a smooth felt surface, batt fibre is attached at least onto the base fabric surface facing the web. The base fabric is typically manufactured by weaving. The base fabric may be directly woven into an endless loop. In that case, however, the width of the weaving machine restricts the length of the base fabric to be manufactured. In addition, the fabric may be woven as a plane. This enables manufacturing base fabrics provided with seam loops. By connecting the joining ends of the base fabrics, a base fabric with the shape of an endless loop can be formed. The seam loops may, however, cause markings on the web to be dried. In addition, adherence of batt fibre to the area provided with seam loops may also pose a problem.